Raspberry Pi Forums

Adco

You are correct. OT. However, I had a minor discussion on page 2 about this and I thought I would give feedback. Hopefully someone will stumble across it and help them somehow. I know that I have found a lot of help readin OT comments.

Adco

I managed to connect my Rpi to a PIC device using a P82B96 buffer chip over a fair distance. Works like a dream. This opens up huge potential for me to develope remote controller boards. I must just work out what would be nice to have points on a board. Things like relays, potentiometers, LEDs, isol...

Adco

Sure, each node would require an extender chip. They are not expensive.

Long distance to me is more than 100m. The mentioned app says 1km is possible.

Adco

Thank you for the idea of jumperable address space and SCL SDA. I will take it into consideration. Some people complaining they want long lines (10m) to their sensor. It would solved their needs. (Most cases temperature sensor outside.) As the board is not assembled or if someone ask me I partially...

Adco

Here's hoping fr another answer.... When I initialise the DS1307, I get "UU" in the feedback block. Once the system shows "UU", I can't release the RTC until I unplug it and reinsert it. How can I release it from the RPi so that I can read or change times? Initially, on a new plug-in, the RTC shows ...

Adco

I tried it and it didn't work. I went back to I2C-1. All good again. I will steer clear of I2C-0 and just work around it. I just wanted to keep the RTC away from the slaves. Having to skip address 68 looked like a mission.

Thanks.

Adco

I'm back! So, I can read and write to a PIC 16F884 set to slave mode! Works like a dream. I am using I2C #1 on the RPi. That is Pin 3 & 5 on the 40 way GPIO header. I want to use I2C #0 as well. I want to put the RTC on that port and leave the slaves on port #1. There will be 100 slaves in total and...

Adco

The i2c-detect man page is here , and the source code is here . It seems to use writes on same addresses and reads on others, but that can be controlled by command line options. dtparam=i2c_arm_baudrate=400000 is how you change the clock rate (see /boot/overlays/README for details of the other thin...

Adco

What happens exactly when I2CDETECT command is issued? My guess is that the system, starting at Device Address 0x03 and ending at 0xff, sends the address out and waits each time for an ACK signal. It then remembers each ACK received and shows it on the table afterwards. In other words, I2CDETECT is ...

Adco

I think I must summarise this solution so that some future user can benefit. This only pertains to someone trying to have control of a DS1307 on a Raspberry Pi 3 running Noobs. 1) In the file /etc/modules have line i2c-bcm2835 and i2c-dev. If snd-bcm2835 is there, comment it out by placing # in fron...

Adco

I can now read all the address using i2cget. Told you, easy peasy.

Adco

:D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D I got it to work!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! It must be the snd-bcm thingy. After I removed the DS1307, rebooted and did the write, my LED flashes at 1Hz. Thanks for the patience and help. Getting this right gives me hope for the future.

Adco

Interestingly, I unplugged the DS1307, did a reboot and then i2cdetect and it shows 68 instead of UU and when I do an i2cset, I don't get the usual error. Nothing else happens but at least there is no error.

Adco

PhilE wrote:Also, slightly off topic, remove snd-bcm2835 from /etc/modules and add "dtparam=audio=on" to config.txt instead.

I took the snd-bcm line out of modules. The second line was already in /boot/config.txt.

No luck. Still UU at 68.

Adco

I recall that there was a stage yesterday when I did i2cdetect and there was 68 instead of UU in the block of info. I don't remember how I got that.

Are you saying that UU means that the system has control and seeing 68 means I have control?

Adco

Some more info on contents of /etc/modules
snd-bcm2835
i2c-bcm2835
i2c-dev

/boot/config.txt
dtparam=i2c_arm=on (there are lots of other lines but only showing what is relevant)

Are there any other files that could contain stuff to be changed or commented out?

Adco

PhilE wrote:Does i2cdetect still show UU?

Do you get an error message?

Still shows UU in location 68.

Only get an error when I try i2cset.

Adco

The bottom line is that you can't get RTC functionality (provided by the ds1307 driver) and user access via i2c-dev at the same time - pick one. 1) run "i2c-detect -y 1" and confirm that 0x68 is in use (UU). If it isn't then something else is going wrong. 2) Find what is loading the driver. It is e...

Adco

Please look at my string: sudo i2cset -y 1 0x68 0x07 0x10. Is it correct? If I am missing something there, nothing will make it work.

Adco

6by9 wrote:See Phil's response on the other thread
(This is why we get annoyed at cross-posting - the multiple threads end up covering the same ground).

I do understand. I am only going to talk to you guys via the other thread.

Adco

The bottom line is that you can't get RTC functionality (provided by the ds1307 driver) and user access via i2c-dev at the same time - pick one. 1) run "i2c-detect -y 1" and confirm that 0x68 is in use (UU). If it isn't then something else is going wrong. 2) Find what is loading the driver. It is e...

Adco

I placed 2 LEDs, in series with the pull-ups, on the SDA and SCL lines on the I2C bus. When I do I2Cdetect, the leds flash briefly as they should. That is when the DS1307 gets read and identified. All good. When I try and read or write to the DS1307, no flashing. Tells me the I2Cset command is inco...

Adco

6by9 wrote:And please don't cross-post - viewtopic.php?f=44&t=98318&sid=74a5149a ... 50#p947543

Again, sorry.

Adco

I can read from the DS1307 using hwclock and i2cdetect but cannot write my own commands to it. I placed 2 LEDs, in series with the pull-ups, on the SDA and SCL lines on the I2C bus. When I do I2Cdetect, the leds flash briefly as they should. That is when the DS1307 gets read and identified. All goo...

Adco

I found dtoverlay in modules. I commented it out and rebooted. Still not communicating with DS1307.

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Re: Optional interfaces (I2C, I2S, SPI) and Device Tree

Re: Optional interfaces (I2C, I2S, SPI) and Device Tree